The present invention relates to an image display apparatus for use in a game apparatus, such as a racing game apparatus or a shooting game apparatus, or a driving simulation apparatus which will be operated by the player or user while seeing a front three-dimensional graphic image from a driver's seat on a car, a spacecraft, or the like, a method of displaying an image with such an image display apparatus, and a computer-readable recording medium which stores a control program for performing such a method.
Image display apparatus combined with racing game apparatus, for example, display an image on a display screen as viewed in front of a driver's seat by a car driver seated on the driver's seat behind a steering wheel. The game player operates the racing game apparatus to play the racing game while seeing the displayed image on the display screen. As the racing game played on the racing game apparatus proceeds, the displayed image changes depending on how the game player operates the racing game apparatus. For example, when the game player turns the steering wheel clockwise, the display screen displays the image of a right-hand area in front of the car to make the car look as if steered to the right. Conversely, when the game player turns the steering wheel counterclockwise, the display screen displays the image of a left-hand area in front of the car to make the car look as if steered to the left. When the game player presses the accelerator pedal, the display screen displays an image moving backwards at an increased speed to make the car look as if it is accelerated. When the game player presses the brake pedal, the display screen displays an image moving backwards at a reduced speed to make the car look as if it is decelerated.
One conventional image display apparatus for use with such a racing game apparatus is shown in FIG. 1 of the accompanying drawings. As shown in FIG. 1, an image 62 of a road and buildings and trees along the road, as viewed from a driver's seat and changed as the game player operates the racing game apparatus, is projected from an image display apparatus 61 onto a flat projection screen at an enlarged scale for the game player to see with ease.
Since the image 62 is projected onto the flat projection screen, the image light from the image display apparatus 61 is applied obliquely to end regions of the flat projection screen while it is applied substantially perpendicularly to a central region of the flat projection screen. Therefore, the image 62 projected onto the flat projection screen is more elongated in the opposite end regions than in the central region of the flat projection screen, and hence looks distorted to the game player. Specifically, when an image 62 of nine circular spots is projected onto the flat projection screen, as shown in FIG. 2 of the accompanying drawings, the central circular spot is displayed as a circular spot on the flat projection screen, but the other circular spots positioned around the central circular spot are displayed as being distorted into elliptical circular spots because the image light of these other circular spots is applied obliquely to the end regions of the flat projection screen. The image light emitted from the image display apparatus 61 through a projection lens thereof travels along a light path which is longer in the end regions than in the central region of the flat projection screen. Consequently, the image 62 projected onto the flat projection screen is more enlarged in the end regions than in the central region of the flat projection screen.
One way of obtaining a three-dimensional and realistic visual perception from images projected in front of the driver's seat is to employ a horizontally long flat projection screen for displaying panoramic images thereon. However, the horizontally long flat projection screen suffers a problem in that the displayed images are greatly elongated or expanded in horizontal end regions of the flat projection screen.
There is known a data conversion process for converting image data with a virtual spherical screen for three-dimensional spatial image rendering. If the known data conversion process is applied to the projected image 62 shown in FIG. 3A of the accompanying drawings, then the image data of the image 62 is converted to image data for displaying a projected image 63. However, if the known data conversion process is applied to a projected image 62b shown in FIG. 3B of the accompanying drawings, then the image data of the projected image 62b is converted to image data for displaying a projected image 63b on a flat screen. The projected image 63b looks unnatural because its shape is distorted as if viewed through a wide-angle lens. The above data conversion process needs a complex hardware arrangement for its execution because the hardware arrangement should perform a data conversion function for an increased data processing rate.